The integrated metabolism of boar taint - towards developing effective strategies to reduce taint.

公猪膻味是指在加热猪肉产品中，来自整头公猪（公猪）的异味或异味。它是由睾丸中产生的高水平的16-雄烯酮类固醇（雄烯酮）和肠菌群中色氨酸产生的粪臭素和其他吲哚积累引起的。通常情况下，雄性猪被阉割是为了防止公猪受到污染，但对阉割的动物福利担忧已经导致一些欧盟国家禁止手术阉割（www.boars2018.com），这在北美成为一个重要问题只是时间问题。在不阉割的情况下控制公猪污染还可以改善生长、提高瘦肉产量、提高饲料利用率和降低饲料消耗，从而通过降低能源成本和减少单位猪肉生产的粪便，提高盈利能力并减少猪肉生产对环境的影响。许多饲料添加剂和管理措施已经被描述为在不阉割的情况下减少公猪的污染，但对这些处理的反应在个体猪之间有所不同。我们的实验室在了解猪粪化合物的综合代谢方面做出了重大贡献，其总体目标是设计有效的治疗方法来控制猪粪。我们还没有调查个体猪之间公猪感染变异的原因。此外，公猪粪便化合物代谢的某些方面尚未得到充分的探索。这包括16-雄烯类固醇在睾丸和肝脏中的代谢，16-雄烯类固醇在血浆中的转运以及它们被脂肪细胞摄取。肠道微生物组与个体猪的生理对粪臭素从肠道产生和吸收以及肝脏代谢的关系也不完全清楚。对这些过程的更全面的了解可能为开发减少公猪污染的方法提供进一步的机会。我们已经确定了一些与公猪粪便代谢有关的基因中的单核苷酸多态性（snp），目的是开发遗传工具和选择方案来减少公猪粪便。我们现在计划确定突变如何影响这些基因的表达和基因产物的活性，这样我们就可以了解它们是如何改变公猪的污染程度的。我们还可以利用这些基因型信息来制定有效的治疗方案，以减少野猪个体动物的基因型污染。我们的目标是：1；完成公猪粪便代谢特性方面的研究工作；整合代谢、生理和基因组信息来定义导致公猪感染和感染个体差异的过程。利用这些信息开发新的有效的方法来减少公猪的污染而不阉割。

Boar taint is an off-odour or off-flavour in heated pork products from entire male pigs (boars). It is caused by the accumulation of high levels of 16-androstene steroids (androstenone), which are produced in the testis, and skatole and other indoles, which are produced from tryptophan by the gut microflora. Male pigs are normally castrated to prevent boar taint, but animal welfare concerns against castration have led several EU countries to ban surgical castration (www.boars2018.com) and it is only a matter of time before this becomes an important issue in North America. Controlling boar taint without castration would also improve growth, increase lean yield, improve feed utilization and decrease feed consumption, which will improve profitability and reduce the environmental impact of pork production from reduced energy costs and less manure per unit of pork produced. A number of dietary additives and management practices have been described to decrease boar taint without castration, but the response to these treatments varies among individual pigs. Our lab has made significant contributions to the understanding of the integrated metabolism of boar taint compounds, with the overall goal of designing effective treatment methods to control boar taint. We have not yet investigated the causes for the variations in boar taint among individual pigs. Moreover, some aspects of the metabolism of boar taint compounds have not yet been fully explored. This includes the metabolism of 16-androstene steroids in the testis and liver, the transport of 16-androstene steroids in plasma and their uptake by adipocytes. The relationship between the gut microbiome and the physiology of the individual pig on the production and absorption of skatole from the gut and metabolism by the liver is also not fully understood. A more complete understanding of these processes may provide further opportunities to develop methods to reduce boar taint. We have identified a number of Single Nucleotide Polymorphisms (SNPs) in genes involved in boar taint metabolism with the goal of developing genetic tools and selection protocols to reduce boar taint. We now plan to determine how the mutations affect the expression of these genes and the activity of the gene products, so we can understand how they can alter the amount of boar taint. We can also use this genotype information to develop effective treatment protocols to reduce boar taint in individual animals based on their genotypes. Our objectives are: 1. To complete work on the characterization of aspects of boar taint metabolism, 2. To integrate metabolic, physiological and genomic information to define the processes that lead to individual differences in boar taint and 3. To use this information to develop novel and effective methods to decrease boar taint without castration.